Response of a Small Mammal Population Postremediation for an In Situ Oil Pipeline Blowout on the Athabasca Oil Sands.

Two releases from steam assisted gravity drainage (SAGD) wellheads occurred 3 yr apart. To track recovery of the affected areas, red-backed voles were studied 1 and 4 yr later, using population estimates, hepatic detoxification effort, body condition, and tissue metal levels as bioindicators of site recovery. From years 1 to 4, higher ethoxyresorufin-O-deethylase induction was no longer evident, capture rate was lower, and body lead residues were no longer (inversely) correlated with body condition. Environ Toxicol Chem 2019;38:1542-1548. © 2019 SETAC.

A multiple lines of evidence approach for the ecological risk assessment of an accidental bitumen release from a steam assisted gravity drainage (SAGD) well in the Athabasca oil sands region.

To assess the ecological impacts of two independent accidental bitumen releases from two steam assisted gravity drainage (SAGD) wells in the Athabasca oil sands region, a multiple lines of evidence (LOE) approach was developed. Following the release in 2010, action was taken to minimize environmental impact, including the selective removal of the most highly impacted vegetation and the use of oil socks to minimize possible runoff. An ecological risk assessment (ERA) was then conducted based on reported concentrations of bitumen related contaminants in soil, vegetation, and water. Results of biological assessments conducted at the site were also included in the risk characterization. Overall, the conclusion of the ERA was that the likelihood of long-term adverse health effects to ecological receptors in the area was negligible. To provide evidence for this conclusion, a small mammal sampling plan targeting Southern red-back voles (Myodes gapperi) was carried out at two sites and two relevant reference areas. Voles were readily collected at all locations and no statistically significant differences in morphometric measurements (i.e., body mass, length, foot length, and adjusted liver weight) were found between animals collected from impact zones of varying levels of coverage. Additionally, no trends corresponding with bitumen coverage were observed with respect to metal body burden in voles for metals that were previously identified in the source bitumen. Hepatic ethoxyresorufin-O-deethylase (EROD) activity was statistically significantly elevated in voles collected from the high impact zones of sites compared to those collected from the reference areas, a finding that is indicative of continued exposure to contaminants. However, this increase in EROD was not correlated with any observable adverse population-wide biological outcomes. Therefore the biological sampling program supported the conclusion of the initial ERA and supported the hypothesis of no significant long-term population-wide ecological impact of the accidental bitumen releases.

Outbreak of type E foodborne botulism linked to traditionally prepared salted fish in Ontario, Canada.

On April 17, 2012, two adult females presented to the hospital with symptoms of botulism. Patient A displayed shortness of breath, increasing lethargy, ptosis, and fixed and dilated pupils, and was intubated after admission. Patient B presented with shortness of breath, vomiting, and stridor. Both patients consumed a meal consisting of a traditionally prepared salted fish, fesikh, on the evening of April 16 during a gathering to celebrate Sham el-Nessim, an Egyptian holiday marking the beginning of spring. Foodborne botulism was suspected based on symptoms and consumption of potentially hazardous food. Antitoxin was administered to both patients on April 18. Another attendee of the Sham el-Nessim gathering (patient C), who also consumed the implicated food, developed symptoms consistent with botulism on April 18. Clinical specimens from all three symptomatic attendees tested positive for either Clostridium botulinum or type E botulinum neurotoxin. Fesikh remaining from the shared meal contained both type E botulinum neurotoxin and C. botulinum type E organisms. Unsold fesikh shad and fesikh sardines tested positive for C. botulinum type E, while unsold fesikh mullet pieces in oil tested positive for both C. botulinum type E and type E botulinum neurotoxin. After consultation with public health investigators, all fesikh products were voluntarily withheld from sale by the manufacturer prior to laboratory confirmation of contamination. Additional illnesses were likely prevented by these precautionary holds, which underscores the importance of timely public health action based on epidemiological evidence available in advance of laboratory results. This is the first documented outbreak of foodborne botulism associated with fesikh to occur in Canada.

Intestinal toxemia botulism in 3 adults, Ontario, Canada, 2006-2008.

Five cases of intestinal toxemia botulism in adults were identified within an 18-month period in or near Toronto, Ontario, Canada. We describe findings for 3 of the 5 case-patients. Clinical samples contained Clostridium botulinum spores and botulinum neurotoxins (types A and B) for extended periods (range 41-61 days), indicative of intestinal toxemia botulism. Patients' clinical signs improved with supportive care and administration of botulinum antitoxin. Peanut butter from the residence of 1 case-patient yielded C. botulinum type A, which corresponded with type A spores found in the patient's feces. The food and clinical isolates from this case-patient could not be distinguished by pulsed-field gel electrophoresis. Two of the case-patients had Crohn disease and had undergone previous bowel surgery, which may have contributed to infection with C. botulinum. These cases reinforce the view that an underlying gastrointestinal condition is a risk factor for adult intestinal toxemia botulism.

Pulmonary hypertension and long-term mortality in aortic and mitral regurgitation.

BACKGROUND: Outcomes data in patients with aortic regurgitation or mitral regurgitation have been limited to small series with generally <10 years of follow-up. The quantitative impact of pulmonary artery hypertension has not been well described. The purpose of this study was to describe the 15-year mortality of aortic regurgitation and mitral regurgitation. METHODS: Our institution's electronic echocardiography database was queried to identify those patients examined in 1992 and reported to have at least mild aortic regurgitation or mitral regurgitation. Patients were classified by semi-quantitative degree of regurgitation. Pulmonary artery systolic pressure was categorized as normal, borderline, mild, or moderate or greater hypertension (pulmonary artery systolic pressure >40 mm Hg). Age-stratified Cox proportional hazards models compared survival among groups and adjusted for sex, depressed left ventricular ejection fraction, and pulmonary artery systolic pressure. Mortality data were obtained from the 2008 Social Security Death Index. RESULTS: Of 4984 echocardiograms performed in 4050 patients, 1156 patients (28%; aged 72±14 years) had at least mild aortic regurgitation and 1971 patients (49%; aged 69±16 years) had at least mild mitral regurgitation. Overall 15-year mortality in patients with aortic regurgitation was 74% and similar for all grades of aortic regurgitation. Overall 15-year mortality in patients with mitral regurgitation was 71% and got progressively worse with increasing severity grade of mitral regurgitation (63% for mild to 81% for at least moderate-to-severe). For both aortic and mitral regurgitation, moderate or greater pulmonary artery systolic hypertension was associated with increased mortality (in patients with aortic regurgitation, hazard ratio [HR], 1.94; 95% confidence interval [CI], 1.58-2.41, and in mitral regurgitation patients, HR, 1.48; 95% CI, 1.26-1.75). CONCLUSION: Long-term (15-year) survival of patients with aortic regurgitation is poor and is independent of regurgitation severity. In contrast, long-term survival of patients with mitral regurgitation correlates with regurgitation severity. For both groups, moderate or greater pulmonary artery systolic hypertension identified those at highest risk.

Proteomic analysis of Campylobacter jejuni 11168 biofilms reveals a role for the motility complex in biofilm formation.

Campylobacter jejuni remains the leading cause of bacterial gastroenteritis in developed countries, and yet little is known concerning the mechanisms by which this fastidious organism survives within its environment. We have demonstrated that C. jejuni 11168 can form biofilms on a variety of surfaces. Proteomic analyses of planktonic and biofilm-grown cells demonstrated differences in protein expression profiles between the two growth modes. Proteins involved in the motility complex, including the flagellins (FlaA, FlaB), the filament cap (FliD), the basal body (FlgG, FlgG2), and the chemotactic protein (CheA), all exhibited higher levels of expression in biofilms than found in stationary-phase planktonic cells. Additional proteins with enhanced expression included those involved in the general (GroEL, GroES) and oxidative (Tpx, Ahp) stress responses, two known adhesins (Peb1, FlaC), and proteins involved in biosynthesis, energy generation, and catabolic functions. An aflagellate flhA mutant not only lost the ability to attach to a solid matrix and form a biofilm but could no longer form a pellicle at the air-liquid interface of a liquid culture. Insertional inactivation of genes that affect the flagellar filament (fliA, flaA, flaB, flaG) or the expression of the cell adhesin (flaC) also resulted in a delay in pellicle formation. These findings demonstrate that the flagellar motility complex plays a crucial role in the initial attachment of C. jejuni 11168 to solid surfaces during biofilm formation as well as in the cell-to-cell interactions required for pellicle formation. Continued expression of the motility complex in mature biofilms is unusual and suggests a role for the flagellar apparatus in the biofilm phenotype.

Effects of mastic resin and its essential oil on the growth of proteolytic Clostridium botulinum.

Studies were done to determine the effect of mastic resin and its essential oil, alone and in conjunction with ethanol, on the growth of proteolytic strains of Clostridium botulinum in media, and on neurotoxin production in challenge studies with English-style crumpets. Preliminary studies, using a spot-on-the-lawn method, indicated that high levels of mastic resin in ethanol ( approximately 8% w/w) were required for complete inhibition of all strains of C. botulinum tested, but mastic resin in ethanol had a greater anti-botulinal effect than ethanol alone. However, only low levels of mastic oil ( approximately 0.3% v/v) were required for inhibition of proteolytic strains of C. botulinum. Both studies showed a strain specific inhibition, with C. botulinum type A strains being more sensitive to mastic resin and its essential oil than type B strains. However, mastic resin in ethanol proved to be more effective when used as a vapor phase inhibitor applied to cotton pads and placed inside inoculated plates than when added directly to media. While both mastic resin and its essential oil inhibited the growth of proteolytic strains of C. botulinum in vitro, they failed to inhibit neurotoxin production in challenge studies with C. botulinum in English-style crumpets.

Effect of ethanol on the growth of Clostridium botulinum.

Model broth studies were carried out to investigate the effect of ethanol on the growth of proteolytic (group I) strains of Clostridium botulinum. Ethanol extended the pathogen's lag phase, decreased its exponential growth rate, and decreased its final level of growth in the stationary phase. In all cases, botulinum neurotoxin production was associated with growth. Micrographs of C. botulinum cultures grown at 37 degrees C in trypticase peptone glucose yeast extract (TPGY) broths containing 2 and 4% ethanol showed elongation of vegetative cells and interference with cell division. The inhibition of growth and toxin production at the ethanol level predicted (5.5%, wt/wt) was confirmed by microscopy and by the mouse bioassay. A subsequent study was carried out to determine the combined effect of ethanol (0 to 8% [wt/wt]), water activity (aw; 0.953 to 0.997), and pH (6.2 to 8.2) on the probability of the growth of and neurotoxin production by proteolytic strains of C. botulinum (10(3) spores per ml). Growth and neurotoxin production occurred in 1 to 3 days in TPGY broths without ethanol (0%) and in 2 to 4 days in broths containing 2% ethanol regardless of the aw or pH levels (P < 0.005). Growth and neurotoxin production were delayed by an ethanol concentration of 4% ethanol and completely inhibited by a concentration of 6%. At an ethanol concentration of 4%, the probability of growth and toxin production over 365 days (Pt) was influenced by aw and pH. After 365 days, the maximum probability of growth and toxin production (Pmax) was 1 for all but one combination. However, tau, the time it took for 50% of all eventually positive replicates for any given combination of barriers to show growth and/or turbidity, ranged from <3 to 229 days. All tubes of TPGY broths that showed no growth after 365 days were subcultured in fresh TPGY broths. In all cases, growth and toxin production occurred within 24 h at 37 degrees C, indicating the reversible (sporostatic and/or bacteriostatic) effect of ethanol on C. botulinum.